#include<iostream>
using namespace std;

int main(){
    int rideType;
    string driverName[101],passengerName[101],route[101];
    double distance,fare;
    
    cin>>rideType;
    cin.ignore();
    
    if(rideType!=1&& rideType!=2){
        cout<<"Invalid input";
        return 0;
    }
cin.get(driverName,101);
cin>>driverName;
cin.get(passengerName,101);
cin>>passengerName;
cin.get(route,101);
cin>>route;
cin.get(distance,101);
cin>>distance;

if(rideType==1){
    fare=distance*1.5;
}
else if(rideType==2){
    fare=distance*0.8;
}
else{
    fare=distance*0.8;
}
cout<<fare;
return 0;
}